The human posterior maxilla often presents dental clinicians with situations where there is a need to increase the available bone between the schneiderian (sinus) membrane and the floor of the maxillary antrum. For example, because of inadequate bone in the posterior maxilla of some dental patients, augmentation of the sinus floor is required before placement of a dental implant.
An early sinus augmentation technique was presented by H. Tatum Jr. in 1977, later published in “Maxillary and Sinus Implant Reconstructions”, Dent Clin North Am 1986; 30(2):207-229 and first described by P. J. Boyne and R. A. James in 1980, “Grafting of the Maxillary Sinus Floor With Autogenous Marrow and Bone” J Oral Surg 1980; 38(8): 613-616.
Originally Tatum accessed the maxillary sinus through the alveolar ridge crest using various instruments of his own design. Boyne and James later developed a lateral window technique modifying the known Caldwell-Luc procedure. In the Boyne and James technique, a horizontal incision was made in the posterior maxillary vestibule followed by exposure of the lateral osseous ridge wall of the posterior maxilla. An osteotomy window was then created by using burs in the lateral osseous ridge wall. The window of lateral wall was either removed or medially repositioned. The sinus membrane was gently released and reflected upward and an autogenous bone graft was then inserted over the exposed sinus floor. The flap was then replaced and primarily closed. A bladed-type implant was placed at 10-12 weeks following the augmentation procedure.
These fundamental concepts have been retained in contemporary lateral window techniques such as described by C. E. Misch in “Maxillary Sinus Augmentation For Endosteal Implants: Organized Alternative Treatment Plans” Int J Oral Implant 1989: 4:49-58 and by J. N. Garg and C. R. Quinones in “Augmentation of the Maxillary Sinus. A Surgical Technique” Pract Periodontics Aesthet Dent 1997; 9:211-219.
Implants are now often placed at the time of grafting according to the amount of pre-existing bone available for initial stability. However, post-operative complications such as pain or swelling due to extensive surgical trauma may increase patient discomfort.
In 1994, Summers published a method for the sinus augmentation using an osteotome instrument, R. B. Summers “A New Concept In Maxillary Sinus. A surgical Technique” Compendium 1994: 15(2):152-158 and “The Osteotome Technique: Part 3-Less Invasive Methods Of Elevating The Sinus Floor” Compendium 1994: 15(6):698-704. In the Summers technique, after initial implant osteotomy drilling was performed, approximating the sinus floor, an osteotome was inserted to the osteotomy site and gently tapped fracturing and moving the sinus floor superiorly. The fractured sinus bone was pushed up, reflecting the Schneiderian membrane, and various bone graft materials were then added and implants immediately placed.
Recently, modifications of the Summer's technique using spreading and condensing instrumentation and elevating the sinus using various pressure techniques have also been reported. Bori J E. “A new sinus lift procedure: SA-4/‘O’”. Dent Implantol Update 1991; 2(4):33-37; Smiler D G. “The sinus lift graft: basic technique and variations”. Pract Periodontics Aesthet Dent 1997; 9(8):885-893.9; Bruschi G B, Scipioni A, Calesini G, Bruschi E. “Localized management of sinus floor with simultaneous implant placement: a clinical report” Int J Oral Maxillofac Implants 1998; 13(2):219-226; M. Toffler “Site development in the posterior maxilla using osteocompression and apical alveolar displacement” Compend Contin Educ Dent 2001; 22(9):775-784; P. A. Fugazzotto, P. S. De “Sinus floor augmentation at the time of maxillary molar extraction: success and failure rates of 137 implants in function for up to 3 years”, J Periodontol 2002; 73(1):39-44; A. A. Winter A. S. Pollack, R. B Odrich “Placement of implants in the severely atrophic posterior maxilla using localized management of the sinus floor: a preliminary study”. Int J Oral Maxillofac Implants 2002; 17(5):687-695; M. Soltan, D. G. Smiler “Antral membrane balloon elevation”. J Oral Implantol 2005; 31(2):85-90; L. Chen, J. Cha “An 8-year retrospective study: 1,100 patients receiving 1,557 implants using the minimally invasive hydraulic sinus condensing technique”. J Periodontol 2005; 76(3):482-491.
However, the amount of augmentation of the sinus floor and the volume of bone created is limited using the foregoing techniques and it is reportedly difficult in many cases to control the osteotome tapping force in order to produce effective membrane lifting without membrane perforation and on occasion the tapping procedure to fracture the sinus floor or to add bone graft material causes discomfort to the patient during the surgery.
A new minimally invasive sinus augmentation technique is presented herein, called the “Internal Sinus Manipulation (ISM)” procedure, and is designed to facilitate sinus floor augmentation predictably while reducing treatment morbidity.